Needle assembly for drug pump

ABSTRACT

A needle assembly adapted for fluid communication with a cartridge containing a substance to be delivered to a subject, the needle assembly characterized by a biasing device ( 70 ) arranged to apply a biasing force on a needle ( 28, 116 ) to cause the needle ( 28, 116 ) to protrude outwards of a housing ( 30, 112 ) to pierce the subject, and biasing device release apparatus ( 60 ) including a biasing device arrestor ( 62 ) that initially blocks movement of the biasing device ( 70 ) and which releases the biasing device ( 70 ) when the safety latch ( 32, 122 ) moves to a position that permits moving the needle holder ( 26, 118 ) to cause the needle ( 28, 116 ) to protrude outwards of the housing ( 30, 112 ).

FIELD OF THE INVENTION

The present invention generally relates to external drug pumps, andparticularly to a needle assembly for a drug pump, particularly suitablefor elderly, invalid or physically challenged persons.

BACKGROUND OF THE INVENTION

External drug pumps are typically used to deliver to patients substanceswhich contain large molecules which cannot be digested when administeredorally, such as insulin. Typically, the pump is adhered to the abdomenof the patient and delivers the substance to the patient via a cannulaor needle that is inserted into the patient's skin.

U.S. patent application Ser. No. 12/345,818 filed Dec. 30, 2008, and PCTPatent Application PCT/US09/69552, filed Dec. 27, 2009, to the sameinventor, describe a needle assembly for administering a drug from avial. (The terms “drug” and “substance” are used interchangeablythroughout the specification and claims, and encompass any materialadministered to a subject. The term “cartridge” throughout thespecification and claims encompasses any container for a drug, such asbut not limited to, a cartridge, vial, syringe, bottle, ampoule and manymore, and is not limited to any size or shape.) The needle assemblyincludes a needle held in a needle holder, and an activation mechanismfor activating delivery of the substance through the needle, such as apush button that initiates the delivery of the substance. The activationmechanism includes a safety latch that prevents the needle from prickinga person accidentally and prevents inadvertent administration of thedrug. The safety latch initially impedes movement of the needle holder.When the safety latch is placed on the subject, the safety latch movesto a position that permits moving the needle holder to cause the needleto protrude outwards of the housing to pierce the subject to allowadministration of the substance to the subject.

A problem of this prior art needle assembly is that elderly, invalid orphysically challenged persons may find it difficult to push the pushbutton to activate delivery of the substance.

SUMMARY OF THE INVENTION

The present invention seeks to provide a needle assembly for a drugpump, particularly suitable for elderly, invalid or physicallychallenged persons, thereby solving the problem of the prior art, as isdescribed more in detail hereinbelow.

There is thus provided in accordance with an embodiment of the presentinvention a needle assembly adapted for fluid communication with acartridge containing a substance to be delivered to a subject, theneedle assembly including a needle held in a needle holder, the needleholder confined to move in a housing, and an activation mechanism foractivating delivery of the substance through the needle, the activationmechanism including a safety latch that initially impedes movement ofthe needle holder, wherein when the safety latch is placed on thesubject, the safety latch moves to a position that permits moving theneedle holder to cause the needle to protrude outwards of the housing topierce the subject to allow administration of the substance to thesubject.

In accordance with an embodiment of the present invention the safetylatch is pivotally mounted on a base about a pivot. The safety latch maybe arranged to selectively pivot in and out of a complimentary shapedgroove formed in the base.

In accordance with an embodiment of the present invention the safetylatch includes a first arrestor at a distal end thereof and a secondarrestor proximal to and spaced from the first arrestor, the first andsecond arrestors being arranged for selectively arresting motion of theneedle holder.

In accordance with an embodiment of the present invention the safetylatch initially impedes movement of the needle holder by being in aposition wherein the first arrestor abuts against an ear that projectsfrom a bottom portion of the needle holder, thereby arresting movementof the needle holder.

In accordance with an embodiment of the present invention when thesafety latch is placed on the subject, the safety latch moves to aposition such that the first arrestor moves away from the ear of theneedle holder to permit movement of the needle holder.

In accordance with an embodiment of the present invention a controlbutton is provided that has a shaft. A slanted tongue protrudes from aperiphery of the shaft at a lower end thereof. When the safety latch isplaced on the subject and the control button is moved, the slantedtongue applies a force against a ramp formed on the needle holder,thereby causing the needle holder to move and to rotate as the needlemoves outwards of the housing. The needle holder can rotate sufficientlyso that the ear is arrested by the second arrestor. Moving the safetylatch off the subject causes the second arrestor to move away from theear and causes the needle holder to continue to rotate due to theslanted tongue still applying a force on the ramp. The needle holderrotates until the slanted tongue moves off the ramp, whereupon theneedle holder moves so that the ear gets caught on a shoulder formed onthe housing, thereby trapping the needle in the housing.

In accordance with an embodiment of the present invention when thecontrol button is moved so that the slanted tongue applies the forceagainst the ramp, the control button becomes locked in the housing.

BRIEF DESCRIPTION OF THE DRAWINGS

The present invention will be understood and appreciated more fully fromthe following detailed description taken in conjunction with thedrawings in which:

FIG. 1 is a simplified illustration of apparatus for administering asubstance to a subject, from the prior art (U.S. patent application Ser.No. 12/345,818 or PCT Patent Application PCT/US09/69552);

FIG. 2 is a simplified illustration of a safety latch of the prior artapparatus in the down position, this being the nominal (starting)position as long as the apparatus has not yet been placed upon theuser's body, and a needle holder cannot be pushed down;

FIG. 3 is a simplified illustration of the prior art safety latch in theup position, which is the position when the apparatus has been placedupon the user's skin;

FIG. 4 is a simplified illustration of lifting the prior art apparatusoff the patient's body after finishing the drug administration, whichcauses the safety latch to move back to the down position;

FIG. 5 is a simplified illustration of the prior art needle holdermoving back up and getting stopped in the up position with the needleretracted back into the housing of the apparatus;

FIG. 6 is a simplified illustration of biasing device release apparatusused in administering a substance to a subject, constructed andoperative in accordance with an embodiment of the present invention;

FIG. 7 is a simplified illustration of a safety latch of the biasingdevice release apparatus of FIG. 6 in the up position, which is theposition when the apparatus has been placed upon the user's skin;

FIG. 8 is a simplified illustration of an actuator moving a biasingdevice arrestor out of a housing so as not to block a biasing devicewhich can urge a needle of the apparatus to pierce a patient's skin, inaccordance with an embodiment of the present invention;

FIG. 9 is a simplified illustration of the biasing device urging theneedle to a piercing position, in accordance with an embodiment of thepresent invention; and

FIG. 10 is a simplified illustration of the biasing device releaseapparatus lifted off the patient's body after finishing the drugadministration, which causes the safety latch to move back to the downposition and the needle to be retracted back into the housing.

FIGS. 11A and 11B are simplified perspective illustrations of thebiasing device release apparatus employed in another apparatus (drugpump) for administering a substance to a subject, constructed andoperative in accordance with an embodiment of the present invention

FIG. 12 is a simplified illustration of the inside of the apparatus inthe position of FIGS. 11A-11B;

FIGS. 13A and 13B are simplified perspective illustrations of theapparatus of FIGS. 11A-11B, in a second stage, after application of theapparatus on the patient's body, in accordance with an embodiment of thepresent invention;

FIG. 14 is a simplified illustration of the inside of the apparatus inthe position of FIGS. 13A-13B;

FIG. 15 is a simplified perspective illustration of the apparatus ofFIGS. 11A-11B, in a third stage, in which the needle protrudes out ofthe pump and is inserted in the body, in accordance with an embodimentof the present invention;

FIG. 16 is a simplified illustration of the inside of the apparatus inthe position of FIG. 15;

FIGS. 17A and 17B are simplified perspective illustrations of theapparatus of FIGS. 11A-11B, in a fourth and final stage, after removingthe apparatus from the patient's body, in which a protector blocks theneedle after use, in accordance with an embodiment of the presentinvention; and

FIG. 18 is a simplified illustration of the inside of the apparatus inthe position of FIGS. 17A-17B.

DETAILED DESCRIPTION OF EMBODIMENTS

Reference is now made to FIG. 1, which illustrates apparatus 10 foradministering a substance, for example, insulin, to a subject, from theprior art (U.S. patent application Ser. No. 12/345,818 or PCT PatentApplication PCT/US09/69552.

A cartridge 12 (also referred to as a vial, the terms being usedinterchangeably) is mounted on a housing base 14. For some applications,a cartridge piercing mechanism 18 is movably (e.g., rotatably) coupledto housing base 14 and pierces the distal end of cartridge 12. Thesubstance to be administered flows from cartridge 12 to an activationmechanism 20 via a tube (not shown). The activation mechanism 20 has acontrol button 22 and is typically coupled to the housing base 14. Theactivation mechanism 20 is configured to insert a cannula and/or aneedle through the subject's skin and to deliver the substance via thecannula and/or the needle. The embodiments of the invention aredescribed with reference to a needle alone, but apply as well to aneedle disposed in a cannula or any other delivery device. The term“needle” is used throughout the specification and claims to encompassall such delivery devices.

Apparatus 10 typically includes a motor, a battery and a control unit(all not shown). After the needle has penetrated the skin of thepatient, the control unit controls operation of the motor to administera controlled amount of the substance to the patient at a controlled rateof delivery. Of course, the needle assembly of the present invention canbe used in other applications and does not have to be used with acontrolled motorized delivery system.

Reference is now made to FIGS. 2 and 3, which illustrate a safety latchof the prior art. Control button 22 has a shaft 24 which is arranged tomove (vertically downwards in the sense of the drawings) against aneedle holder 26 (FIG. 3) which holds a needle 28. The shaft 24 and theneedle holder 26 are both confined to move in a (e.g., tubular) housing30, but there is a difference in their movements. Shaft 24 is confinedto translate downwards in housing 30 with no rotation. In contrast,needle holder 26 can not only translate but can also rotate in housing30, as will be explained more in detail below.

The movement of needle holder 26 is selectively impeded by a safetylatch 32, which is pivotally mounted on housing base 14 about a pivot34. Safety latch 32 is arranged to selectively pivot in and out of acomplimentary shaped groove 37 (FIG. 1) formed in housing base 14.Safety latch 32 includes a first arrestor 36 at a distal end thereof anda second arrestor 38 proximal to and spaced from the first arrestor 36.The arrestors may be shaped as lugs or other projections or any otherstructure suitable for arresting motion of needle holder 26 as will beexplained below.

FIG. 2 shows safety latch 32 in the down position, which is its nominal(starting) position as long as apparatus 10 has not yet been placed uponthe user's body. In this position, first arrestor 36 abuts against anear 40 that projects from a bottom portion of needle holder 26. It isnoted that pushing ear 40 down against a surface 42 of first arrestor 36will not cause downward movement of needle holder 26 because this willsimply pivot first arrestor 36 about the pivot 34 causing anothersurface 44 of first arrestor 36 to abut against the bottom surface ofhousing 30. Thus, when safety latch 32 is in the down position, needleholder cannot be pushed down (in the sense of the drawing of course).

FIG. 3 shows safety latch 32 in the up position (that is, it has pivotedupwards about pivot 34), which is the position when apparatus 10 hasbeen placed upon the user's skin. First arrestor 36 has been moved outof the way of ear 40 of needle holder 26, so that control button 22 cannow be pressed down to move needle holder 26 downward, thereby piercingthe patient's skin. Needle 28 remains inserted in the patient for theduration of the drug administration. Pressing control button 22 downcauses shaft 24 to become locked in the down position in housing 30,such as by means of one or more splines (not shown here), which radiallyproject outwards from shaft 24, sliding past one or more chamferedresilient tongues (not shown here) mounted in housing 30. After thesplines slide past tongues, the splines become locked in place by theaction of the tongues resiliently snapping back in place over them.

After finishing the drug administration, apparatus 10 is lifted off thepatient's body. This causes safety latch 32 to move back to the downposition as shown in FIG. 4, thereby moving second arrestor 38 away fromear 40. A biasing device 47, such as a leaf spring biased between firstarrestor 36 and housing base 14, may be employed to impart a returningforce on safety latch 32 to move it back to the down position. A slantedtongue 50 applies a downward force on ramp 52, thereby permitting needleholder 26 to rotate counterclockwise until slanted tongue 50 slides offramp 52. At this point, needle holder 26 jumps back up and ear 40 getscaught on a shoulder 54 formed on housing 30 as shown in FIG. 5. In thisposition, needle holder 26 cannot move back down because of ear 40 beingarrested against shoulder 54. Accordingly, needle 28 is trapped backinside apparatus 10 in a safe position, and apparatus 10 may be safelydiscarded.

Reference is now made to FIG. 6, which illustrates biasing devicerelease apparatus 60 for administering a substance to a subject,constructed and operative in accordance with an embodiment of thepresent invention. Elements of the present invention which are identicalor equivalent to elements described above for the prior art aredesignated with the same reference numerals.

As previously described, in the prior art apparatus, after drugadministration, needle holder 26 retracts back into housing 30 by theaction of counterclockwise rotation and ear 40 getting caught onshoulder 54 formed on housing 30. In the present invention, this samearrangement can be used. Alternatively or additionally, a biasing device59, such as a coil spring, can be used to retract needle holder 26 backinto housing 30 after drug administration. Biasing device 59 is arrangedto apply an urging force on needle 28 in the direction of arrow 57(upwards in the sense of the drawings).

With biasing device release apparatus 60, the user does not have toapply a force for the mechanical operation of the device. Rather eitherthere is no control button to push down, or alternatively the controlbutton can be touch sensitive or be operated on slight pressure, and abiasing device 70, such as a coil spring, is released to push downneedle 28, as described below. Biasing device 70 is stronger thanbiasing device 59. Biasing device 70 is arranged to apply an urgingforce on needle 28 in the direction of arrow 71 (downwards in the senseof the drawings).

Apparatus 60 includes a biasing device arrestor 62, such as a tongue ordog mounted on a shaft 63, and enters housing 30 through an aperture 64.An actuator 66 is provided for moving biasing device arrestor 62. Forexample, actuator 66 may be, without limitation, a step motor, linearactuator, solenoid and the like. In the non-limiting illustratedembodiment, actuator 66 is a step motor that rotates a drive gear 68that meshes with a spur gear 72 mounted on shaft 63. Biasing devicearrestor 62 may be threadedly mounted on a threaded portion 74 of shaft63.

A safety latch position sensor 76 is provided for sensing when safetylatch 32 moves to the up position of FIG. 7. Safety latch positionsensor 76 may be, without limitation, a reed switch or any other kind ofswitch or sensor suitable for sensing the movement of safety latch 32 tothe up position. Safety latch position sensor 76 is in communicationwith a controller 78, which controls operation of actuator 66. Asmentioned above, the prior art apparatus 10 typically includes a motor,a battery and a control unit. Actuator 66 can be this same motor andcontroller 78 may be this same control unit, or they may be separateunits.

FIG. 6 shows safety latch 32 in the down position, which is its nominal(starting) position as long as the drug administering apparatus has notyet been placed upon the user's body, corresponding to FIG. 2 of theprior art. As described above, in this position, needle holder 26 cannotbe pushed down (in the sense of the drawing). In the present invention,in this position, biasing device arrestor 62 is inside housing 30 andblocks biasing device 70, preventing it from pushing down on needle 28.

FIG. 7 shows safety latch 32 in the up position (corresponding to FIG. 3of the prior art), which is the position when the drug administeringapparatus has been placed upon the user's skin. Safety latch positionsensor 76 senses the movement of safety latch 32 to the up position andsignals controller 78 that safety latch 32 is now in the up position.Controller 78 thereupon commences operation of actuator 66. In apreferred embodiment, controller 78 initiates operation of actuator 66after a predetermined time delay (e.g., 5-15 seconds) to ensure that thedrug administration apparatus was indeed placed on purpose on thepatient for administering the drug.

When operated, actuator 66 moves biasing device arrestor 62 out ofaperture 64, as shown in FIG. 8. In the non-limiting illustratedembodiment, actuator 66 rotates drive gear 68, which in turn rotatesspur gear 72 to rotate shaft 63. Rotation of shaft 63 causes biasingdevice arrestor 62 to move linearly out of aperture 64 along threadedportion 74. When biasing device arrestor 62 reaches the end of threadedportion 74, it rotates freely on shaft 63 and moves no further.

As soon as biasing device arrestor 62 has moved out of aperture 64,biasing device 70 is no longer blocked and it now pushes down on needle28 (overcoming the weaker biasing device 59), as shown in FIG. 9. Needle28 now piercing the patient's skin and administers the drug. Asdescribed for the prior art apparatus, shaft 24 becomes locked in thedown position in housing 30.

After finishing the drug administration, the apparatus is lifted off thepatient's body. As described for the prior art apparatus, this causessafety latch 32 to move back to the down position as shown in FIG. 10,and needle 28 is trapped back inside the apparatus in a safe position,and the apparatus may be safely discarded.

Reference is made to FIGS. 11A-11B and 12, which illustrate the biasingdevice release apparatus 60 employed in another apparatus 110 (alsoreferred to as drug pump 110) for administering a substance to asubject, constructed and operative in accordance with an embodiment ofthe present invention. Elements of biasing device release apparatus 60are designated with the same reference numerals as above.

The activation mechanism 20 is also employed in this embodiment.However, as opposed to the previously described embodiments, inapparatus 110, the needle is not retracted back into the housing afterdrug administration, but there is a protector that blocks the needleafter use for preventing accidental needle pricks, as is described morein detail hereinbelow.

In apparatus 110, the cartridge (not shown) is mounted on a housing base112 (or simply housing 112), as shown in FIGS. 11A-11B. A hollow needle(not shown) is provided in housing 112 for piercing a septum at a distalend of the cartridge. The substance to be administered flows from thecartridge eventually to a needle 116 held in a needle holder 118(confined to move in a housing 117), as controlled by biasing devicerelease apparatus 60. As described above, with biasing device releaseapparatus 60, there is no control button to push down. Instead biasingdevice 70 is released to push down needle 116, in the same manner asdescribed above.

The movement of needle holder 118 is selectively impeded by a safetylatch 122, which is pivotally mounted on housing base 112 about a pivot124. Safety latch 122 is arranged to selectively pivot in and out of acomplimentary shaped groove 126 formed in housing base 112. Safety latch122 may be biased by a biasing device 128, such as a coil spring. Safetylatch 122 is formed with a needle opening 129 to allow needle 116 topass therethrough.

In the first stage shown in FIGS. 11A, 11B and 12, before operation,safety latch 122 blocks the path of needle 116 for preventing againstinadvertent, premature activation (the blocking mechanism as described,for example, in U.S. patent application Ser. No. 12/345,818 or PCTPatent Application PCT/US09/69552).

A microsensor 120, such as a photo-microsensor, may be provided forsensing the position of the needle for use in conjunction with thecontrol unit to control the various stages of the operation of the pump.In addition to the photo-microsensor 120, another sensor 130 (FIG. 12)may be provided for sensing the position and operation of safety latch122. For example, sensor 130 may be a magnet sensor 130 that senses if amagnet 132 mounted on the distal end of safety latch 122 is near sensor130 or not.

In the second stage shown in FIGS. 13A, 13B and 14, apparatus 110 isplaced on the patient's body (not shown), and safety latch 122 haspivoted to be flush with housing base 112. Needle 116 is now aligned tobe advanced through needle opening 129 of safety latch 122. Anindication may be provided that pump 110 is on the body by magnet sensor130 sensing the magnet 132 on safety latch 122 (or any other suitablesensing mechanism). (It is noted that biasing device release apparatus60 is not shown in FIG. 14 for the sake of simplicity.)

As described above, biasing device 70 of biasing device releaseapparatus 60 is then released to push down needle 116 into the patient'sbody, in the same manner as described above. Needle 116 advances throughneedle opening 129 of safety latch 122 to the position shown in FIGS. 15and 16 (third stage of operation). The sensing mechanism may provide anindication indicating that the needle 116 is inserted. Needle 116 stayslocked in the insertion position.

Reference is made to FIGS. 17A, 17B and 18. In the fourth and finalstage of operation, after administrating the substance, pump 110 isremoved from the patient's body, thereby releasing safety latch 122 topivot to the down position. However, since needle 116 is alreadyprotruding out of the housing and remains locked in the protrudedposition, needle 116 does not align with needle opening 129 of safetylatch 122, as seen best in FIG. 18. Thus, safety latch 122 serves as aprotector that blocks the tip of needle 116 after use of pump 110 forpreventing accidental needle pricks.

It will be appreciated by persons skilled in the art that the presentinvention is not limited by what has been particularly shown anddescribed hereinabove. Rather the scope of the present inventionincludes both combinations and subcombinations of the features describedhereinabove as well as modifications and variations thereof which wouldoccur to a person of skill in the art upon reading the foregoingdescription and which are not in the prior art.

1-8. (canceled)
 9. Apparatus (110) comprising: an activation mechanism(20) operative to deploy a needle (116) to protrude out of a housing(112); and a safety latch (122) movably mounted on said housing (112)and formed with a needle opening (129) to allow said needle (116) topass therethrough, wherein said safety latch (122) has a first positionwherein said needle (116) is aligned to pass through said needle opening(129) and a second position wherein said safety latch (122) is movedwith respect to said housing (112) and said needle (116) is blocked by aportion of said safety latch (122) distanced from said needle opening(129).
 10. Apparatus (110) according to claim 9, wherein said safetylatch (122) is pivotally mounted on said housing (112) about a pivot(124) and in the second position said safety latch (122) is pivoted awayfrom said housing (112).
 11. Apparatus (110) according to claim 9,wherein said safety latch (122) is pivotally mounted on said housing(112) about a pivot (124) and in the first position said safety latch(122) is flush with said housing (112).
 12. Apparatus (110) according toclaim 9, further comprising a microsensor (120) that senses a positionof said needle (116).
 13. Apparatus (110) according to claim 9, furthercomprising a sensor (130) that senses a position of said safety latch(122).
 14. Apparatus (110) according to claim 9, wherein in the secondposition said needle (116) is misaligned with said needle opening (129).15. Apparatus (110) according to claim 9, wherein said safety latch(122) is biased by a biasing device (128).
 16. A pump (110) foradministering a fluid to a subject comprising; a housing (112); a needleholder (118) including a needle (116) having a distal end, the needleholder (118) being movable within the housing (118) from a firstposition in which the needle (116) is located entirely within thehousing (112) and a second position in which at least the distal end ofthe needle (116) extends outside of the housing (112) for engaging theskin of the subject and administering the fluid to the subject; a safetylatch (122) including a needle opening (129) extending therethrough, thesafety latch (122) being movable from a first position in which thesafety latch (122) is flush with a surface of the housing (112) with theneedle opening (129) aligned with the distal end of the needle (116) sothat when the needle holder (118) is moved to the second position theneedle (116) extends through the needle opening (129), out of thehousing (112) and into engagement with the skin of the subject and asecond position in which at least a portion of the safety latch (122) isseparated from the housing surface, the needle opening (129) is notaligned with the distal end of the needle (116) and a portion of thesafety latch (122) engages and blocks access to the distal end of theneedle (116).
 17. The pump (110) according to claim 16, wherein thesafety latch (122) is pivotally mounted on the housing (112) about apivot (124) and in the second position the portion of the safety latch(122) is pivoted away from said housing (112).
 18. The pump (110)according to claim 16, further comprising a sensor (120) that senses theposition of the needle holder (118).
 19. The pump (110) according toclaim 16 further comprising a sensor (130) that senses a position of thesafety latch (122).
 20. The pump (110) according to claim 16 whereinsaid safety latch (122) is biased by a biasing device (128).